I have polycystic ovary syndrome(pcos). my weight is ok, so i think i need no exercise to reduce it(i think i am underweight).... how can i cure it?

Control not cure: Thin patients with PCOS should focus on controlling the symptoms such as irregular periods, abnormal hair growth and acne. Usually birth control pills are prescribed. Cure may not be possible. Of course the diagnosis of PCOS should be confirmed and other problems excluded.

Low Carb!: It isn't only about weight, but what you eat. Most PCOS females put weight on the middle, and may weigh a normal weight! But PCOS is part of metabolic syndrome, with hyperinsulinemia a major issue. Cut back drastically on carbs. Metformin can help, as well!